I think it's better to go slightly "OOC" in response to torture than simply shrugging it off. Torture screws people up, and while some folks recover more quickly than others, scars happen and there is some kind of recovery time needed.

I don't know the character well enough to say for certain, but I'd be fairly confident in calling Laharl's reactions "character development re:extraordinary circumstances" rather than "lol OOC burn the witch".